1. Field of the Invention:
The present invention relates to a workpiece supporting device for supporting a workpiece by center members.
2. Description of the Prior Art:
The conventional workpiece supporting device for supporting a workpiece by center members is somewhat satisfactory in performing its intended function. However, the device is complicated in construction, thus necessarily making it relatively expensive in cost.
Moreover, since the hydraulic actuator for moving the holding shaft carrying the center member toward and away from the workpiece is also connected to act on a spring for applying a holding force to the workpiece being supported by the center members, the spring is excessively compressed each time the hydraulic actuator is operated to retract the holding shaft from the workpiece. Therefore, there is a possibility that the spring will be damaged by repeated excessive compression.
Furthermore, such conventional device cannot meet the requirement that the holding shaft be accurately adjusted to a desired position for supporting, for example, workpieces with the same length but with slightly different center bores.